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Diffstat (limited to 'opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d_gain_c.cpp')
| -rw-r--r-- | opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d_gain_c.cpp | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d_gain_c.cpp b/opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d_gain_c.cpp new file mode 100644 index 0000000..9cc14c0 --- /dev/null +++ b/opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d_gain_c.cpp @@ -0,0 +1,214 @@ +/* ------------------------------------------------------------------ + * Copyright (C) 1998-2009 PacketVideo + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either + * express or implied. + * See the License for the specific language governing permissions + * and limitations under the License. + * ------------------------------------------------------------------- + */ +/**************************************************************************************** +Portions of this file are derived from the following 3GPP standard: + + 3GPP TS 26.073 + ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec + Available from http://www.3gpp.org + +(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) +Permission to distribute, modify and use this file under the standard license +terms listed above has been obtained from the copyright holder. +****************************************************************************************/ +/* +------------------------------------------------------------------------------ + + + + Filename: d_gain_c.cpp + Functions: d_gain_c + + ------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + pred_state = pointer to sturcture type gc_predState. MA predictor state + mode = AMR mode (MR795 or MR122) of type enum Mode + index = received quantization index of type Word16 + code[] = pointer to innovation codevector of type Word16 + pOverflow= pointer to value indicating existence of overflow (Flag) + + Outputs: + pred_state = pointer to sturcture type gc_predState. MA predictor state + gain_code = pointer to decoded innovation gain of type Word16 + pOverflow = 1 if there is an overflow else it is zero. + + Returns: + None. + + Global Variables Used: + None + + Local Variables Needed: + None + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + Function : d_gain_code + Purpose : Decode the fixed codebook gain using the received index. + +------------------------------------------------------------------------------ + REQUIREMENTS + + + +------------------------------------------------------------------------------ + REFERENCES + + d_gain_c.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 + +------------------------------------------------------------------------------ + PSEUDO-CODE + + + +------------------------------------------------------------------------------ +*/ + + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ +#include "d_gain_c.h" +#include "typedef.h" +#include "mode.h" + +#include "oper_32b.h" +#include "cnst.h" +#include "log2.h" +#include "pow2.h" +#include "gc_pred.h" + +#include "basic_op.h" + +/*--------------------------------------------------------------------------*/ +#ifdef __cplusplus +extern "C" +{ +#endif + + /*---------------------------------------------------------------------------- + ; MACROS + ; Define module specific macros here + ----------------------------------------------------------------------------*/ + + + /*---------------------------------------------------------------------------- + ; DEFINES + ; Include all pre-processor statements here. Include conditional + ; compile variables also. + ----------------------------------------------------------------------------*/ + + /*---------------------------------------------------------------------------- + ; LOCAL FUNCTION DEFINITIONS + ; Function Prototype declaration + ----------------------------------------------------------------------------*/ + + + /*---------------------------------------------------------------------------- + ; LOCAL STORE/BUFFER/POINTER DEFINITIONS + ; Variable declaration - defined here and used outside this module + ----------------------------------------------------------------------------*/ + + + /*---------------------------------------------------------------------------- + ; EXTERNAL FUNCTION REFERENCES + ; Declare functions defined elsewhere and referenced in this module + ----------------------------------------------------------------------------*/ + + /*---------------------------------------------------------------------------- + ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES + ; Declare variables used in this module but defined elsewhere + ----------------------------------------------------------------------------*/ + + /*--------------------------------------------------------------------------*/ +#ifdef __cplusplus +} +#endif + +/*---------------------------------------------------------------------------- +; FUNCTION CODE +----------------------------------------------------------------------------*/ +void d_gain_code( + gc_predState *pred_state, /* i/o : MA predictor state */ + enum Mode mode, /* i : AMR mode (MR795 or MR122) */ + Word16 index, /* i : received quantization index */ + Word16 code[], /* i : innovation codevector */ + const Word16* qua_gain_code_ptr, /* i : Pointer to read-only table */ + Word16 *gain_code, /* o : decoded innovation gain */ + Flag *pOverflow +) +{ + Word16 gcode0, exp, frac; + const Word16 *p; + Word16 qua_ener_MR122, qua_ener; + Word16 exp_inn_en; + Word16 frac_inn_en; + Word32 L_tmp; + Word16 tbl_tmp; + Word16 temp; + /*-------------- Decode codebook gain ---------------*/ + + /*-------------------------------------------------------------------* + * predict codebook gain * + * ~~~~~~~~~~~~~~~~~~~~~ * + * gc0 = Pow2(int(d)+frac(d)) * + * = 2^exp + 2^frac * + * * + *-------------------------------------------------------------------*/ + + gc_pred(pred_state, mode, code, &exp, &frac, + &exp_inn_en, &frac_inn_en, pOverflow); + + index &= 31; /* index < 32, to avoid buffer overflow */ + tbl_tmp = index + (index << 1); + + p = &qua_gain_code_ptr[tbl_tmp]; + + /* Different scalings between MR122 and the other modes */ + temp = sub((Word16)mode, (Word16)MR122, pOverflow); + if (temp == 0) + { + gcode0 = (Word16)(Pow2(exp, frac, pOverflow)); /* predicted gain */ + gcode0 = shl(gcode0, 4, pOverflow); + *gain_code = shl(mult(gcode0, *p++, pOverflow), 1, pOverflow); + } + else + { + gcode0 = (Word16)(Pow2(14, frac, pOverflow)); + L_tmp = L_mult(*p++, gcode0, pOverflow); + L_tmp = L_shr(L_tmp, sub(9, exp, pOverflow), pOverflow); + *gain_code = (Word16)(L_tmp >> 16); /* Q1 */ + } + + /*-------------------------------------------------------------------* + * update table of past quantized energies * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * + *-------------------------------------------------------------------*/ + qua_ener_MR122 = *p++; + qua_ener = *p++; + gc_pred_update(pred_state, qua_ener_MR122, qua_ener); + + return; +} + + + + |